The IRS considers a tax return to be filed on time if it is postmarked by the filing due date, April 15.
The Postal Service is now warning tax-filers that the postmark date on the envelope may not be the day the return was mailed at a post office. There’s also a similar warning on the Find USPS Locations website:
If you want to ensure your return receives a postmark on April 15, says the Postal Service, you should take it to your local Post Office and ask for a manual postmark at the retail counter. There’s no charge for the service.
The need for an alert like this is a new USPS cost-saving initiative called Regional Transportation Optimization.
Under the RTO, mail is no longer collected at the end of the day and transported to a processing center, where letters are scanned and postmarked on the same day. Instead, the mail sits in the back of the post office overnight, to be collected the next morning when the day’s mail is dropped off.
In other words, the two trips between the processing center and the post office are combined into one. The RTO cuts transportation costs, but it adds a day to delivery times and means that the electronic postmark won’t be applied until the next day.
The RTO applies only to post offices more than 50 miles from one of the new network’s 56 Regional Processing and Distribution Centers (RPDC). Those within 50 miles continue to get the evening collection, so returns mailed at one of these post offices will usually get the same-day postmark.
While alerting customers to the postmark issue, the Postal Service does not inform them if their post office is subject to RTO or not. There are no signs at the RTO post offices, no notices in PO boxes, no readily accessible list of where RTO has been or will be implemented.
The Postal Service has, however, been sharing lists with the Postal Regulatory Commission. These lists are updated monthly, and they show the ZIP Codes of the post offices where the RTO has been “activated.” (The latest list is here.)
| Place, State ZIP | RTO Status | Activation Date | PO Address | Campus Site | RPDC |
|---|---|---|---|---|---|
| Weems, VA 22576 | RTO Activated | 10/28/2023 | 3960 WEEMS RD | RICHMOND VA RPDC |
You can use our “RTO Status Checker” app, which is based on lists shared with the PRC, to see if RTO has already been activated at your post office. Just enter the ZIP code or “city, state,” and hit “enter” on your key pad.
The Checker will show if and when your post office was activated for RTO. If it says “RTO TBA,” it means the post office is eligible for RTO and will eventually be activated. If it says “Not RTO,” it means the post office is within 50 miles of a RPDC and not directly affected by the postmark issue.
Here’s a map of where the RTO has been activated as of April 1, 2026. The blue shows where it’s been implemented; yellow where it will be implemented over the coming months; orange shows the areas within 50 miles of a RPDC. You can search the map using a place, state or a ZIP Code followed by US.
There’s more about the USPS postmark policies here, and there’s a USPS Fact Sheet here. The list on which the map and status checker are based is here. For more about the RTO, see our RTO Dashboard.
— Steve Hutkins